


Awesome!

by Cunning_Linguist



Category: Undertale (Video Game)
Genre: Alternate Universe - Swapfell (Undertale), Alternate Universe - Underfell (Undertale), Alternate Universe - Underlust (Undertale), Alternate Universe - Underswap (Undertale), Fluff and Humor, Multi, Polyamory, Reverse Harem, Smut, Spitroasting, Threesome
Language: English
Status: In-Progress
Published: 2019-11-15
Updated: 2019-11-15
Packaged: 2021-01-31 11:07:27
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,616
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21445216
Author URL: https://archiveofourown.org/users/Cunning_Linguist/pseuds/Cunning_Linguist
Summary: In which you prove the existence of the multiverse in the most unconventional of ways.
Relationships: Papyrus/Reader, Sans/Reader, Sans/Reader/Papyrus
Comments: 26
Kudos: 80





	Awesome!

**Author's Note:**

> Special thanks to Rejtely for their work as beta!

Some days start out awesome. Some days are pretty shitty right from the get-go. Some days really make you wonder at your life choices and where they lead you.

Today is one of those days.

It actually started out really nice! You managed to wake up right before your alarm went off, a peaceful start rather than the godawful blaring noise that ensured you didn’t oversleep. Rolling out of your ridiculously comfy bed and skipping downstairs gained you the sight of your sweet boyfriend Papyrus, busily cooking breakfast for the three of you in the kitchen. He greeted you with a swift nuzzle to the cheek as he plated up pancakes. You cheerfully helped set the table as he brought over the food and some matcha tea. Your favorite - and no one else’s- but Papyrus likes to spoil you.

Just as everything was ready, your other boyfriend blipped into existence at his seat at the table, greeting you with a bleary, “mornin babe. Paps. Looks good. Breakfast looks pretty yummy too.” You blushed a little as you gently nudged Sans’ shoulder with your own, happily digging in as you heard Papyrus give a cheerful little “nyehheheh” at both the praise and his brother’s cheesy flirting with you.

The meal was eaten in fairly quiet peace, the delicious sweetness of the food, the comfortable affection between you three, and the lack of sufficient time for the caffeine to kick in rendering conversation unnecessary. You hummed in satisfaction as you leaned back in your chair, smiling happily at your soulmates.

That’s right, soulmates. When monsters surfaced they brought with them the unequivocal knowledge that souls do in fact exist. Lesser known to the general public but no less of a fact, was that soulmates are again a factual reality. You were blessed enough to have two in the form of the skeleton brothers, and you couldn’t be more pleased. Whatever were the odds, you wondered, of the monsters you opened your home to just after the Emergence being the very ones who made your soul sing like no other? While the three of you had yet to reach the point in your relationship where you finalized the bond in an act involving the very culmination of your beings, things were going very well indeed. Yes, you were very satisfied with your life right now. You were very satisfied last night too, you recalled with a lascivious smirk. Sans had surprised you last night, but you really enjoyed it. As your eyes drifted over to Papyrus, your grin widened. Tonight will be his turn with you, and you could hardly wait. Papyrus caught your gaze and blushed a little at the look on your face, but then surprised you with a bold wink. He laughed when you pretended to fan yourself in response.

All good things come to an end eventually, pleasant breakfasts included. In short order you were kissing your boys as they headed out to Papyrus’s convertible to go to work. Papyrus worked at the Embassy for all Monsters. Sans worked in the Royal Labs, helping a joint team of monster and human scientists devise a plan for The Core 2.0 to be built in California. The monsters’ potential to solve humanity’s energy crisis was one of the reasons they were granted rights so quickly and easily after the Emergence.

Left alone for the day, you ascended the stairs to your studio in the loft and got to work. As a freelance artist and novelist, you had a very flexible schedule, but you liked to keep to your routines. The morning flew by in a blur as you typed out a couple of chapters for your next novel and began outlining your latest commission. In all honesty you found furry porn kind of boring and repetitive to draw, but it was a very lucrative niche. Noting the time, you saved your work and started down the stairs for lunch.

Not even halfway down, the front door opened, and Papyrus walked in just as Sans materialized from a shortcut into the living room. You smiled widely at your boyfriends as they exchanged startled and hesitant looks.

“Hey Sans, hey Pap! Welcome home! What are you two doing here?” You greeted them happily, hugging them in turn. The boys fidgeted nervously.

“I MISSED YOU TODAY, LOVE.” Papyrus admitted as he pulled you into a lingering embrace. “I’VE BEEN THINKING OF YOU ALL MORNING. I JUST CAN’T GET YOU OFF MY MIND TODAY...ESPECIALLY AFTER HOW LOUD YOU WERE LAST NIGHT.” He smirked a little. “I WAS HOPING TO ENJOY YOUR COMPANY OVER THE LUNCH BREAK, BUT I WASN’T EXPECTING SANS TO HAVE THE SAME IDEA...ARE YOU NEVER SATIATED, BROTHER?”

“heh, sorry bro. didn’t mean to keep you up last night. must have been pretty hard on you.” Sans drawled. “how am i ever supposed to be sated when our human is just so delectable? it’s lunchtime and I haven’t had a drink since last night, can’t blame me for being so thirsty.”

“NYEH! SANS! I YOU DESIST WITH YOUR LEWD PUNNERY IMMEDIATELY!” Papyrus cast a smoldering look down at you, even as you sniggered at the wordplay. He rolled his eye lights and sighed at the sight, then smirked. “YOU’RE ONE TO TALK ABOUT BEING THIRSTY. I HAVEN’T HAD A DRINK SINCE THE NIGHT BEFORE LAST!”

You decided that now was as good a time as any to mention something that had been on your mind for awhile. “Well then...it would be cruel and unusual punishment to deny a monster who hasn’t had a drink in so long. Why don’t I take care of you both?”

“oh Hell yes babe.”

“NYEH, BOTH OF US? AT THE SAME TIME? HOW LEWD, DARLING...”

Well, that’s one on board. Time to up your game. Lucky for you, you knew just how to push Pap’s buttons...and he was already worked up enough to seek you out over lunch, a rarity. Oh yes, you were going to have a great time. You pressed yourself fully against Papyrus, grinding into him lightly. A light, startled moan slipped past his teeth as you stretched up to whisper against the side of his skull.

“Oh please, Papyrus? I want you so much. I don’t want to wait, I want to please you, both of you. I don’t want to make you wait either. I know you need me, you came all the way home just to fuck me, didn’t you?”

Papyrus was panting lightly as he clutched you to him, grinding against you in return as his bones rattled softly. You nuzzled against the vertebrae of his neck and kept up the dirty talk, making sure each sinful word that fell from your lips puffed lightly over his sensitive bones.

“Please, Papaya, I want you. Don’t you want to bend me over and fuck me? Fill me up with that delicious cock of yours and pound me senseless? You don’t even have to wait, we could do it right here, on the couch. You could fuck me from behind while Sans fucks my mouth, what do you think of that? I’m yours, both of yours, how hot would it be to fill me up while watching me choke on your brother’s cock? Maybe we could even do it twice, and you could fuck my mouth next. What do you say, hmm? Don’t you want to fill me with both of your magic?”

Papyrus answered you with a loud moan as he pressed his mouth to yours, kissing you with fervent hunger. A flare of pink-orange light flashed through your closed eyelids as his magic manifested, a new hardness pressing insistently into your hips. His hand wandered down to squeeze your ass as his tongue invaded your mouth as he deepened the kiss.

Sans had been quietly waiting while you worked your own magic (heh) on his brother. When Pap succumbed to your insistent charm, he made his move, stepping up behind you to nuzzle and nip at the soft flesh of your delicate neck. His hands came around your waist, stroking at your supple stomach and caressing the bones of your hips through the thin layer of flesh that covered them. God how he loved humans, particularly this one. So soft, so alien. Ridiculously strong in soul and magic but pitifully weak in the flesh, compared to a monster. And he was lucky enough to have this amazing creature as his mate, one that even loved his brother probably as much as he did, though in very different ways. He gently tugged at you as he backed towards the couch, you and his brother following in his wake.

Feeling the cushions against the back of his knees, Sans flopped backwards into the corner of the couch and spread his legs invitingly, his white lab coat spread around them. “c’mon angel, come here. you haven’t had lunch yet have ya? i’ve got a nice treat to fill you up with, but ya gotta work for it.” He winked boldly at you as you turned around in Pap’s arms, then dropped to your knees before him. Sans grinned as he grabbed your arms and hauled you up against his chest and into a deep kiss. He shoved his tongue into your mouth roughly as his magic snapped into place, rushing from his soul and manifesting his cock so abruptly he almost felt dizzy. Just as well that he was sitting down. Sans groaned as he felt your small hands sneak under his shirt, one stroking a floating rib while the other teased and caressed his spine.

“fuck, angel, yes. just like that. stars, do you even know what you’ve been doing to me all day? i haven’t been able to stop thinking about last night. then you go and show me just how kinky you can be now. the thought of getting double dicked turns you on, huh? you’re as thirsty for our cocks as we are for you. you’re a bit of a freak, aren’t you angel?” Sans growled into your ear as you gasped and shivered against him. You grabbed at the fat cock that was tenting his slacks and playfully pinched the tip in retaliation. Sans yelped at the sudden sensation and you smirked.

“oooh, you little tease. i’m going to get you for that.”

Papyrus finally abandoned the last of his nerves at the display in front of him, the sounds of your pleasure causing him to harden near painfully. He stepped up behind you decisively and grabbed at your hips. You moaned as he pressed his pelvis against your ass, his bulge pressing insistently against your core through the fabric of your shorts.

“YOU SOUND DELICIOUS, DARLING. ENJOYING YOURSELF? I AM. YOU'RE MAKING SUCH LOVELY SOUNDS FOR MY BROTHER...I WONDER JUST HOW MUCH MORE YOU’LL MAKE FOR ME.” Papyrus ran his hands up your back, beneath your light tank top. He stroked sensually back down your sides as he rubbed himself against you, delighting in the moan that slipped past your plush lips.

All three of you startled lightly as a strong gust of wind blasted the house. The branches of the willow tree in the yard knocking against the walls as the windows shook in their frames.

“Jeez, that was a doozy. It’s turning into quite the windstorm...hope the power doesn’t go out. But if it does, I’ll still have two nice big lights to see by hm?” You cheekily winked over your shoulder at Papaya as you caressed the bulge in Sans’ pants.

“hehe. think you’re real funny, don’t you angel? think i’ve got a better use for that smart mouth of yours.” Sans deftly undid his belt and unbuttoned his slacks, groaning as his glowing blue member sprang free from its prison. You cooed appreciatively and wasted no time, happily licking your way from base to tip and planting a lush kiss to the throbbing head. Sans moaned unashamedly as he trembled at the tortuously light touches of your soft lips and tongue.

Papyrus reached around to your front as you continued to tease his brother’s cock, stroking his hands up your chest to play with the small nipples there. You sighed at the gentle pleasure, the soft brush of air against Sans’ cock causing him to tremble beneath you. Papyrus stroked downwards, caressing your lightly muscled stomach as he brushed past down the button of your shorts. Slowly, sensually he undid them and pulled them down to rest just beneath your knees. The sight of your pulsing entrance trembling with want sent a fierce shiver of need through his bones.

The first lap of his tongue at your core wrenched a sharp cry of pleasure from you. Papyrus’s magic sent delicious tingles through you as it stretched and pleasured you. He groaned, sending subtle vibrations into you. You cried out as your legs shook.

“Please Papaya, please, I’m ready. Take me, take me now, I want your cock so badly..” You couldn’t bear the ache inside you, canting your hips invitingly back towards him. Papyrus withdrew with a pleased chuckle. You whimpered at the loss but gasped as you felt him tease you with the tip of his cock. After several moments you were about to start begging again when he finally pushed inside, filling you slowly, his girth stretching you burning with pleasure just this side of pain. The sound that escaped you was outright lewd as you reveled in the feeling.

Sans’ legendary patience began to slip at the sight and sounds before him. He gently grabbed your head, guiding it down as he shoved his cock into your mouth. His hand shakily carded through your short hair as he moaned. “c’mon angel, take it, that’s it. Mnng, yeah, suck me. just like that. take it, that’s it, take our cocks. you’re loving this, aren’t you? our very own little cock slut.” You moaned at the dirty talk as Papyrus started to fuck you in earnest from behind. Soon the room was filled with a chorus of moans, growls, and gasped expletives as the three of you lost yourselves in the bliss of the act. A backdrop of vague rattles and bangs sounded as the storm continued outside. The lights flickered strongly, but none of you paid it any mind.

....you really should have.

__________________________________________________________________________________________

In the basement of your home resided Sans’ personal lab and workshop. One corner was dominated by a large, ominous machine that was covered in a dusty tarp. The power surge driven by the storm caused the machine to power on. It flared brighter and brighter as the energy built. The cascade reached a tipping point just as another, more powerful surge jolted through the house. A blinding flash of light filled the basement. As the light faded, eight skeletal bodies were left in its wake.

“what the fuck just happened.”

“WHERE ARE WE? WHO ARE YOU?”

“IDENTIFY YOURSELVES AT ONCE, MISCREANTS!”

“papy, what’s going on? who are all these guys?

“WHAT THE HELL ARE YOU WEARING?! COVER YOUR SHAME!”

“ooh, now that’s not very nice, lover.”

“get the fuck away from me!”

“LANGUAGE!”

“hey, let’s all take a deep breath and a step back here.”

“SPEAK FOR YOURSELF! IS THIS YOUR FAULT? WHERE ARE WE?”

“i don’t know any more than you do, pal.”

“HEY, DO YOU ALL HEAR THAT?”

At that, the group of skeletons stilled, each straining to listen in the dark of the lab. Muted moans and cries filtered down from above.

“IS SOMEONE HURT? WE SHOULD GO SEE IF THEY NEED HELP UP THERE!” The short, energetic skeleton dressed in grey armor rushed towards the stairs he could faintly see in the dark.

“bro, wait-” cursing, a lanky skeleton wearing an orange hoodie followed after him.

“IF SOMEONE IS INJURED, THEN SURELY THE GREAT AND TERRIBLE CAPTAIN OF THE ROYAL GUARD MUST INVESTIGATE! SANS, MOVE YOUR LAZY ASS AND COVER ME!”

“sure thing, boss”

“WHAT THE HELL ARE YOU TALKING ABOUT, I AM THE MALEFICENT CAPTAIN OF THE ROYAL GUARD AND _I_ WILL INVESTIGATE! MUTT! FOLLOW!”

“yes, m’lord.”

Four skeletons rushed up the stairs. The remaining two brothers looked at each other.

“...I DON’T THINK THAT SOUNDED QUITE LIKE PAIN, BROTHER.”

“heh. neither do i. this should be fun. wanna go see what the action is?”

“OH YES. WE SHOULDN’T LET EVERYONE ELSE HAVE ALL THE FUN!”

The last two skeletons ran lightly up the stairs.

_________________________________________________________________________

Things had gotten very heated between you, Sans, and Papyrus. Both brothers slammed into you at a furious pace, loud cries of pleasure puncturing the feverish slap of pelvic bones against your flesh as they chased their ends. You could feel yourself tightening around Papyrus as Sans pistoned into your mouth. Almost there...just a little more…

The muffled bang was easily dismissed as part of the sound of the storm. The sudden shouting, however, caused all of you to start - and scramble to cover yourselves.

“IS EVERYONE OKAY? WE WERE IN A STRANGE DARK ROOM DOWNSTAIRS SUDDENLY AND HEARD NOISES FROM UP HERE? IS SOMEONE HURT? ...OH MY! OH STARS, I-I-I’M SO SORRY! I DIDN’T SEE ANYTHING! OH MY GOD..”

“oh, _nice_.”

“WHAT IS THE SITUATION HERE - DEAR GOD, WHY? COVER YOURSELVES, I DIDN’T NEED TO SEE THAT!”

“is that a human? huh. kinda small, aren’t they?”

“WHO ARE YOU? WHY ARE YOU...CANOODLING WITH A HUMAN! BOTH AT ONCE! OUT HERE IN THE OPEN! HAVE YOU NO SHAME? I INSIST THAT YOU TURN THEM OVER TO ME AT ONCE SO I CAN HARVEST THEIR SOUL!”

“whoa there pal, no touching the human.”

“OH GOODNESS, NO NEED TO BE SO SHY! MIND IF WE JOIN IN? I’VE NEVER BEEN WITH ANOTHER SKELETON BEFORE. I BET IT’LL BE A LOT OF FUN!”

“two at once? you’re a talented one, aren’t you. why don’t you let us join your fun and see if you can handle four~~?”

Sans and Papyrus hastily pulled out of you and tucked themselves back into their pants at the invasion, eyelights wide and slightly wild. You fell to the ground in an ungraceful heap at the motion. Sans grabbed your arms and hauled you to your feet as Papyrus quickly tugged your shorts up for you. Once they were satisfied that you were sufficiently covered, you all turned to the crowd flooding your living room.

Shocked silence reigned for a moment as you all took in the sight of each other. You felt overwhelmed at the sight of the skeletons. Eight of them, four short and four tall. The mortified blush on your cheeks faded as your mind kicked into gear.

“Sans and Papyrus, I presume?” You received a few hesitant nods in response. Turning to Sans, a slightly manic grin split your face. “Well, how does it feel? You can go down in history as the monster who proved the multiverse theory while in the middle of a threesome on his living room couch.”

The silence was broken by a chorus of loud guffaws, shocked giggles and disgusted scoffs. Papyrus covered his face with his hand. “REALLY, DARLING? THAT’S WHAT YOU’RE GOING WITH?”

Papyrus turned to the others as Sans continued to chuckle at you. “I AM SO SORRY YOU HAD TO WITNESS THAT...DISPLAY. I CERTAINLY WASN’T EXPECTING GUESTS, EVEN MORE SO FROM MY BASEMENT! WHERE DID YOU ALL COME FROM?”

Various replies of “the Underground” or “snowdin” sounded from the crowd. An edgy looking Sans dressed in red and black expanded on the answer. “from what it sounds like, we was all mindin’ our own business and just suddenly ended up by your machine with our bros. it don’t look like you was actively using it, so i’m guessing you didn’t mean to pull all of us here.” He smirked. “definitely not given that show we were treated to. seems like you’ve got something, or rather some_one_, better to be doing than messing with that goddamn machine”. The Sans leered at you as he spoke. You raised your chin and winked in reply. Hell yes, you’re way more awesome than any weird old machine and you were damn proud of it! His surprised blush and chuckle delighted you.

“CERTAINLY NOT! AND! COULD WE NOT SPEAK OF THAT AGAIN PLEASE?”

Oh your poor Papaya. He’s going to be mortified for quite a long while over this, isn’t he?

Sans, your Sans, decided to weigh in. “i’m guessing the power surges this windstorm is causing must have had something to do with it. i’ll take a look at the machine and see what i can find out.”

“IN THE MEANTIME, WHY DON’T YOU INTRODUCE US TO THIS SWEET LITTLE THING?” A tall, scantily clad Papyrus purred.

You decided to introduce yourself, adding “yes, I’m a human, but you don’t need my soul. Go ahead and look outside, this is the surface.”

“REALLY?” one of the Sanses shouted. He had blue eye lights and a large bandanna around his neck that matched, so cute! “SOMEONE MENTIONED THAT BEFORE, I THINK. PAPY! COME ON, LET’S GO LOOK AT THE SURFACE!!” He rushed past you, not to the living room windows but making a beeline for the french doors that led to your backyard. The other seven skeletons followed excitedly with no prompting necessary, all desperately eager to see the surface.

In the sudden quiet you, Papyrus, and Sans all looked at each other.

“Well. That was about as awesome as what went down during the Emergence. Am I a magnet for weird, embarrassing scenarios during history in the making or what?”

Papyrus groaned and covered his face again while Sans laughed.

**Author's Note:**

> I'm deciding if I want this to be a one shot or a series. Let me know in the comments if you want to see where this goes!
> 
> Come chat with me!  
Tumblr: https://www.tumblr.com/blog/rivan20  
Discord: Rivan #5769


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